Abstract

The microstructural changes associated with the formation of lithium tantalate waveguides after high repetition rate ultrafast laser inscription has been investigated by confocal micro-Raman experiments. While the laser beam focal volume is characterized by significant lattice damage, no reduction of Raman mode strength has been observed at the guiding region, suggesting the preservation of the nonlinear optical coefficient in the waveguide. A general blueshift of the Raman modes has been observed at the guiding region, suggesting lattice compression as the dominant mechanism of waveguide formation.

Received 19 November 2008Accepted 04 February 2009Published online 24 February 2009

Acknowledgments:

This work has been supported by the Universidad Autónoma de Madrid ad Comunidad Autonoma de Madrid (Project No. CCG07-UAM/MAT-1861), by the Spanish Ministerio de Educacion y Ciencia (Grant No. MAT 2007-64686), and by the National Science Foundation of the U.S. (Grant No. 0556086)